One key to resolving this issue will be whether or not you allow yourself to recognize the very interesting fact that the thoughts that are kicking your rear end right now are coming from the same mind that convinces you to do things...which it then turns around and abuses you for doing, saddling you with guilt, frustration, and self-loathing; and yet, the guilt, frustration, and self-loathing is still that very same voice!
If there were a 'friend' of yours who convinced you to do what is against your deepest wish, and upon doing it that 'friend' then commenced to unleashing pure hell on you for doing it, you'd look straight at that person and tell them to shut the heck up and get away from you.
Why on earth would you allow yourself to be slapped around now by the voice in your head that daily passes it off as your intimate friend, but, in truth, is not?
Fundamentally, there are some habits you want to change - to replace them with their healthier, enriching opposites. This is undeniable. These constitute your deep, sincere wishes.
There is a mechanical, sleeping part of your mind that operates like an automaton - and when you are not 'in control' of yourself it is because you've basically fallen asleep at the wheel and this trickster (your conditioned cravings, thoughts, negative feelings, etc.) is running the show.
If you ever decide that you want to be ever more in control of yourself, the skill you'll need to learn is to stay awake on the bridge of the ship - to grow more alert in the wheelhouse, so that you lose the habit of drifting off, of surrendering your attention to 'habits' - you will need to acquire the skill to operate your mind consciously, quietly, in each and every present moment that you can remember.
You should listen to some of my radio show broadcasts that speak to these things.
You do not need to lose weight.
All you need is to gain control of your attention in the present moment so that you become aware of the true nature of what hypnotizes you into thinking that the emptiness it causes can be filled by things that it can use against you.